Stanley Johnson today appeared to flout face mask guidelines for the third time in a week - hours after sharing public pictures of himself wearing a covering.
The Prime Minister's father was pictured on Monday wearing the face mask underneath his mouth and nose - commonly referred to as a chin strap - as he waited for a train.
Hours earlier, Mr Johnson had shared a photo of himself on the Tube, wearing a mask, while sat alongside Work and Pensions Minister Therese Coffey and MP John Penrose.
He captioned the image: "Masks firmly in Place on the Jubilee Line with @theresecoffey and @JohnPenroseNews after #CPF session at the ‘virtual’ Conservative Party Conference."
It came after he was forced to apologise after going shopping in west London without wearing a mask . He was also seen without a covering while waiting in a Greek airport .
Speaking after the latest picture emerged on Monday, Mr Johnson said it was only his third day back in London and he was "learning every day".
"I have certainly been absolutely wearing a mask on the Underground trains and public transport and so on," he said. "I don’t notice that everybody wears masks on the platform.
"I have certainly got my mask on the platform, I agree it is below my nose."
He added: "This has been a fast learning curve for me and I’m certainly grateful for the vigilance of my fellow travellers.
"Thanks to all of you for sending photographs of me every time I appear in public. I am really taking a huge, huge… I’m taking this very seriously."
Speaking on Monday, the Prime Minister's official spokesman said he did not know if Mr Johnson had spoken to his father.
"I know the Prime Minister’s father has set out that he recognises his error and fully understands it’s vital for everyone to abide by the rule on face coverings and social distancing," he said.
“The Prime Minister is very clear that everyone needs to follow the guidance on hands, face, space and the rules apply to all of us."
Asked if the Prime Minister would support his father being fined for repeatedly breaching the rules, the spokesman replied: “It’s not for me to advise the police in relation to individual cases.
"That’s not how it works in this country but the PM is very clear that the rule is for everyone and everyone needs to follow them."
Mr Johnson was pictured with his mask pulled down around his chin as he read a book at a Greek airport last week, in images obtained by the Daily Star. Greek law states masks must be worn at all times in public spaces.
A police source told the newspaper: “It does not matter who you are, celebrity or no. We are all doing our best to stop the virus spreading, and we will be very hard on those who do not listen.
“You must wear a mask, and if you don’t we will give a big fine. He should be warned. We will not go easy on him."
The source added: "He is not above the law and we will not hesitate to arrest and fine anyone who comes here."
He was also photographed shopping without a face covering in a newsagent in Maida Vale on Tuesday.
He issued an apology after he was pictured in the London corner shop, saying he was not "maybe not 100 per cent up to speed" with the rules after three weeks abroad.
Following the first incident at a shop in London, Downing Street said the Prime Minister believed his father should have followed the rules.
The Prime Minister’s official spokesman said: “You have heard the Prime Minister’s father apologise for his mistake.
“He recognises his error and fully understands that it is vital for everyone to abide by the rules on face coverings and social-distancing.
“The PM is certainly clear that the rules apply to everyone and everybody should follow them."
A representative for Stanley Johnson has been contacted by the Standard for comment.
